The present invention covers an autotransfusion process and an autotransfuser device with separation of aqueous and blood phase and removable bags.
A highly performing single use autotransfuser device is known and has been the object of an application for a French patent under No 2 600 537.
Such an autotransfuser device is particularly useful in certain circumstances when known hospital procedures are inappropriate. It is well recognized that in case of a delicate surgical procedure, whether due to length or high risk of haemorrhage, practitioners organize for appropriate quantities of blood.
This type of practice is admissible for planned procedures, in medically equipped sites, and close to properly supplied blood banks.
Nevertheless, one can remark on the high cost and sometimes difficult supply especially for some more specific blood groups. Moreover, once the blood has been delivered, stocks unused during the procedure cannot be kept for long, presently not beyond 35 days, thus requiring the proper management of dates and generating heavy administrative constraints for medical centres whose vocation this is not.
It is also known that in some countries, it is difficult in the case of a blood transfusion to have any certainties as to the quality and purification_of the blood, which puts transfused patients at risk. There could in particular be potential contamination with HIV virus, hepatitis, tuberculosis or syphilis, as well as with undetected or undetectable pathogens such as non conventional pathogens.
Moreover, in case of transfusion, it is more judicious to recover and transfuse back at least part of an individual's own blood, with his or her antibodies and all of his or her other molecules, rather than injecting him or her with blood from a blood bank.
There are also other situations, especially natural disasters or war situations, when the supply of blood is made impossible by the actual quantities required. Autotransfusion then remains the only solution.
Some populations do not accept to be transfused with blood from another person for religious reasons, personal convictions or other reasons. Once again, in such cases autotransfusion is the only way of saving lives.
It is necessary to recall as well that in the case of accidents, the time available for intervention can be very short and in such short intervals, supply from a blood bank is extremely difficult not to say impossible, especially so in countries without the organizations or structures for collecting, controlling and implementing blood transfusion. In such cases, autotransfusion with the recovery of haemorrhage blood represents an option which is immediately available.
It is necessary to distinguish two special applications, the first one intra operative and the second post operative, some procedures being concerned by both applications, with an autotransfusion during the procedure which is continued after the procedure through the recovery of the haemorrhaged blood with an outside drain, usually during the 6 hours following the procedure.                In the case of the intra operative transfusion, it is necessary to be able to reinject the recovered blood directly to the patient, almost in continuous mode. As is known, this blood must necessarily be diluted when collected and anti-coagulant products must be added in order to preserve its transfusional quality.        
These actions seem necessary because when using a vector liquid for the haemorrhage blood recovered, the red blood cells can thus be protected from direct physical traumas when coming into mechanical contact with filters and other tubing. This dilution in a vector liquid also reduces the contact of red blood cells with air thus restricting their haemolysis significantly. The recovered blood must then be reinjected into the patient's body but there are some major issues to be faced.
In the case of over diluted blood one may cause hypervolemia phenomena due to these overly important transfused liquids and hypocoagulability due to the transfusion of an excess of anti-coagulant products.
In order to avoid this occurrence, it is necessary to use extremely complex and expensive equipment to extract the haemodilution liquids, called washing/centrifugal machines.
Moreover, when carrying out an autotransfusion with blood that has been extracted directly and only diluted and complemented with anti-coagulant products, there is a risk of injecting activated or degraded biological substances likely to produce side effects. On might find histamines, kallicreins or kinins, more or less degraded plasma factors, which it is better to remove or else small proteins issued from cell traumas.